Why is everyone looking at this card as a contructed-card? It is in my opinion not made for constructed, most of you are completely right. It doesn't really fit any warlock deck or meta.

However, the value and potential of this card in arena is just beyond insane.

In arena you will almost always be very low on cards during the later turns.You draw this, clear everything and get to draw a few more cards? It's a guaranteed win in almost every situation described above.

There are also many more discovery/get a random card/spell-mechanics than before, so this card will see play, just not from any warlocks putting it in their deck. Not every card needs a niche or reason.